A TUI is a computer-implemented interface that allows a user to program and to manipulate program commands by using a telephone handset to communicate with a computer. At present, there are primarily two types of TUIs available: DTMF/tone-based and voice-based. In a tone-based TUI, control commands are generated using normal touch-tone dialing. For example, a user can touch buttons on a keypad to generate DTMF signals. Conventional telephones have a keypad including 12 buttons and, therefore, 12 possible combinations of tones. In contrast, for a voice-based TUI, commands are generated by reciting words or phrases. Voice activated controls recognize the recited words or phrases and identify the command.
A tone-based TUI provides a hierarchy of prompts consisting of a menu of options selected by touch-tone dialing. Once the TUI has been activated, the user is provided with an announcement of the options available at the present level in the menu structure. A TUI utilizing a DTMF interface instructs the user to press a keypad button associated with a number in order to initiate a desired action.
For example, a typical announcement in a DTMF-controlled TUI may provide the following menu of options for a voice mail system: “To listen to your messages, press 1; To change your voice mail greeting, press 2; . . . To disconnect, press 9.” If the user presses a button represented by the number 1, the voice mail system plays the first voice mail message in the mailbox. This is an example of a single level of options in a tree menu structure. However, if the user presses a button represented by the number 2, the system goes to a different level of options in the tree menu structure. At each subsequent level the user enters, a new announcement is heard by the user. Each announcement instructs the user of a new set of available options. The user cannot skip levels of command options as a result of the tree-like menu structure for the DTMF-controlled interface. The user has to navigate through each level until a desired option is encountered, thereby making this tone-based TUI tedious to navigate.
On the other hand, a voice-based TUI utilizes a “flat” menu structure of options. Instead of pressing keys on the keypad of a telephone handset, the user states a voice command that instructs the system to perform an action. For instance, a user would simply state “Listen to my messages” or “Send a new message” without listening to a prompt identifying all of the possible options available to the user. In other words, upon the user entering the voice-based TUI, no announcement is made by the system and the user simply states the desired option, if known. If the user is not sure what to do, the user can say “Help” and the system responds by presenting the user with a list of the system's voice commands. However, because a voice-based TUI uses a flat menu structure, the user will not be provided with the hierarchy of prompts typically encountered in the tone-based TUI.
A voice-based TUI sometimes has difficulty responding to voice commands in noisy environments. Moreover, in public, if a user encounters a voice-based TUI, additional confidentiality may be desired. For example, the user may experience difficulty responding verbally in an environment where it is possible to be overheard. In order to allow the user to respond in private, the voice-based TUI must be exited or the user may simply fail to complete the purpose for which the call was made.
One technique to overcome the problems associated with both the DTMF and voice interface techniques is to utilize a voice-based TUI that can also accept the entry of DTMF commands. This technique is referred to as a voice-based hybrid TUI. Unlike a tone-based TUI, the user is not prompted in the voice-based hybrid TUI to press a button on a keypad to select an option. The user, however, must either know the corresponding button for a voice command or must ask the system for help.
Another technique to overcome the problems associated with both the tone-based and voice-based interface techniques is to utilize a tone-based TUI with integrated voice recognition. This technique is referred to as a tone-based hybrid TUI. An example of an announcement in a tone-based-hybrid TUI may state: “To listen to your messages, press or say 1 now; To change your voice mail greeting, press or say 2 now; To disconnect, press or say 9 now.”
Both hybrid TUIs are implemented by using the same command mode of the core TUI on which they are based. For example, the tone-based hybrid TUI utilizes a tone-based command mode and the voice-based options are implemented from the core tone-based command mode. In contrast, the voice-based hybrid TUI uses a voice-based command mode and the tone-based options are performed while operating in this voice-based command mode. These known hybrid systems face operational difficulties because the options of a subsequently desired operating mode are implemented from within the originally initiated operating mode. For example, a tone-based hybrid TUI for a voice mail system may have a “Barge-In” capability that allows a user to implement voice command options without leaving the tone-based command mode. The user simply “talks over” the prompts and, in response, the tone-based-hybrid TUI recognizes the voice command and implements the corresponding option of the tone command mode. However, a Barge-In feature only allows the user to operate within the original command mode. To activate the other command mode, the user has to terminate the call and begin anew. There is no mechanism for changing the active command mode in a prior TUI system at any time during a call.
For the foregoing reasons, there is a need for a single TUI that combines tone-based and voice-based command modes. This integrated TUI should provide the user with access to either command mode and allow the user to switch between the two at anytime. This tone-based/voice-based TUI also should allow both modes to remain functionally distinct rather than having one command mode functioning as the core TUI.